FIG. 1 shows a structural schematic diagram of an electrochemical processing apparatus according to the prior art. As shown in the figure, the electrochemical processing apparatus according to the prior art maintains a stable gap between the processing electrode 20′ and the workpiece 30′ by means of downward feed of the spindle 5′. Thereby, the balance gap required by processing is maintained and the processing precision and surface quality can be achieved as well. When the apparatus performs an electrochemical process, a gap exists between the processing electrode 20′ and the workpiece 30′. The portion material of the workpiece 30′ will thereby precipitate in the electrolyte of the gap due to electrolysis, and thus a shape corresponding to the processing electrode 20′ can be formed on the workpiece 30′. Because the gap is extremely narrow or the external propulsion capability of the circulation of electrolyte is insufficient, the products of electrolysis cannot be removed completely and promptly. Consequently, the processing precision of the workpiece 30′ in the processing region is inferior, or the products of electrolysis will adhere to the workpiece 30′.
FIG. 2 and FIG. 3 show improvements on the drawbacks of the prior art described above. In order to renew the electrolyte in the gap sufficiently, mechanisms such as a crank, and a motor or an up-and-down micro-vibrator 70′ are set on the spindle for connecting to the processing electrode 20′. When an electrochemical process is performed, the processing electrode 20′ will vibrate up and down so that the electrolyte in the gap can be renewed sufficiently. However, the complexity of the apparatus and the processing cost will increase accordingly. Besides, the up-and-down vibration of the electrode varies the width of the gap, resulting in unstable electrolysis owing to varying distribution of electric filed following the vibration, which is disadvantageous to process stability and tracking control of the inter-electrode gap. Furthermore, as shown in FIG. 1, the electrochemical processing apparatus uses the spindle 5′ for driving the processing electrode 20′ to move linearly in the Z-axis and then perform electrochemical process on the workpiece 30′. Thereby the shape of the processing electrode 20′ used in the apparatus complements with the shape on the workpiece 30′. Consequently, it takes long processing time and higher processing cost to fabricate the processing electrode 20′.